In artificial selection, humans provide the selective pressure for species to change and shape the evolution of various breeds. what provides the selective pressure in natural selection?
a) the environment
b) the degree of natural genetic variation in a population
c) disease
d)scientifically trained humans

a) The environment.

Explanation: Natural selection is one of the forces of evolution. Natural selection occurs when individuals in a population have a different reproductive success in certain environment. For example, imagine a mosquitoes population in a insecticide-free envrionment, the non-resistent mosquitoes will be more succesfull that the resistant ones. But when there's insecticide in the environment, the resistent mosquitoes will be more successfull that the non-resistent ones, because they die.

there are 35 white marbles

step-by-step explanation:

y- yellow marbles

4y + 5 = 45

subtract 5 from both sides

4y = 40

divide for from both sides

y = 10

plug in 10 to get 40 yellow marbles then subtract by 5 to get 35 marbles

thus there are only 10 yellow marbles

regents of the university of california v. bakke, 438 u.s. 265 (1978), was a landmark decision by the supreme court of the united states. it upheld affirmative action, allowing race to be one of several factors in college admission policy.